disabled $ ea4('TmJq@p/)F? ۜSec@s,iNdd6dd6dd6dd6dd 6d d 6d d 6dd6dd6dd6dd6dd6dd6dd6dd6dd6d d!6d"d#6d$d%6d&d'6d(d)6d*d+6d,d-6d.d/6d0d16d2d36d4d56d6d76d8d96d:d;6d<d=6d>d?6d@dA6dBdC6dDdE6dFdG6dHdI6dJdK6dLdM6dNdO6d8dP6dQdR6dSdT6d$dU6dVdW6dXdY6dZd[6d\d]6d^d_6d`da6dbdc6ddde6dfdg6dhdi6djdk6dldm6dndo6dpdq6drds6dtdu6dvdw6dxdy6dzd{6d|d}6d~d6dd6dd6dd6dd6dd6dd6dd6dd6dd6dd6dd6dd6dd6ZdS(s The ``assert`` statement ************************ Assert statements are a convenient way to insert debugging assertions into a program: assert_stmt ::= "assert" expression ["," expression] The simple form, ``assert expression``, is equivalent to if __debug__: if not expression: raise AssertionError The extended form, ``assert expression1, expression2``, is equivalent to if __debug__: if not expression1: raise AssertionError(expression2) These equivalences assume that ``__debug__`` and ``AssertionError`` refer to the built-in variables with those names. In the current implementation, the built-in variable ``__debug__`` is ``True`` under normal circumstances, ``False`` when optimization is requested (command line option -O). The current code generator emits no code for an assert statement when optimization is requested at compile time. Note that it is unnecessary to include the source code for the expression that failed in the error message; it will be displayed as part of the stack trace. Assignments to ``__debug__`` are illegal. The value for the built-in variable is determined when the interpreter starts. tasserts Assignment statements ********************* Assignment statements are used to (re)bind names to values and to modify attributes or items of mutable objects: assignment_stmt ::= (target_list "=")+ (expression_list | yield_expression) target_list ::= target ("," target)* [","] target ::= identifier | "(" target_list ")" | "[" target_list "]" | attributeref | subscription | slicing (See section *Primaries* for the syntax definitions for the last three symbols.) An assignment statement evaluates the expression list (remember that this can be a single expression or a comma-separated list, the latter yielding a tuple) and assigns the single resulting object to each of the target lists, from left to right. Assignment is defined recursively depending on the form of the target (list). When a target is part of a mutable object (an attribute reference, subscription or slicing), the mutable object must ultimately perform the assignment and decide about its validity, and may raise an exception if the assignment is unacceptable. The rules observed by various types and the exceptions raised are given with the definition of the object types (see section *The standard type hierarchy*). Assignment of an object to a target list is recursively defined as follows. * If the target list is a single target: The object is assigned to that target. * If the target list is a comma-separated list of targets: The object must be an iterable with the same number of items as there are targets in the target list, and the items are assigned, from left to right, to the corresponding targets. Assignment of an object to a single target is recursively defined as follows. * If the target is an identifier (name): * If the name does not occur in a ``global`` statement in the current code block: the name is bound to the object in the current local namespace. * Otherwise: the name is bound to the object in the current global namespace. The name is rebound if it was already bound. This may cause the reference count for the object previously bound to the name to reach zero, causing the object to be deallocated and its destructor (if